Supercharging control for internal-combustion engines



July 9, 1946.* P. LEBE T SUBERCHARGING CONTROL FOR INTERNAL-COMBUSTIONENGINES Filed Mardh 1:5, 194s width or the main supercharging portscontrol slots. On the other hand the number Patented July 9, 1 946CONTROL FOR IN TER- NAL-COMBUSTION ENGINES SUPERCHARGIN G Pierre Lebet,Arbon, Akticngcsellschaft A zerland A Switzerland, dolph Saurer,

r3 OFFICE assignor to Arbon, Swit- Application March-13, 1943, SerialNo. 479,023 In Germany January 9, 1942' v 7 Claims. (Cl. 12375) Thisinvention relates to internal. combustion engines provided withsuperchargingmeans.

It is an object of this invention to improve the supercharging ing anyseparate control mechanism.

Since the time interval required for the supereharging coincides withthe compression stroke, this interval must be kept as short as possible,since otherwise the supercharging effect wouldbe impaired by theinevitable shortening of the effective compression stroke. Therefore aprerequisite for a satisfactory supercharging effect is the provision oflarge inlet portsin conjunction with high opening and closing speeds.

It hasalready beenproposed to provide supercharging ports in thecylinder wall which are controlled by a ring valve formed withcorresponding slots, in order to obtain higher opening and closingspeeds.

According to the present invention in engines of this latter typethecrossesectional area of passage of the supercharging. ports isincreased considerably and.hiehopenin and closing speeds areobtained'without additional control members being required, by formingthatportion oi the; cylinder wall which adjoins the row at sunerchargingports and has not v.y tteen am by the working piston when the supchargine period. is ended. with an addition l row of p rt controlled byadditional slots in the ring valve, these additional ports and slotsbeing however so. dimensioned, that during each stroke of the ring,valve whereby the first row of supercharging ports isuncovered, theadditional ports are first uncovered and then covered again. In otherWords, the circumferential width of the addi than the tional orts andslots. is made smaller and their of additional ports and slots and alsotheir axial length may be greater than, the number and length of themain supercharging ports and their control slots.

In the drawing affixed to this specification and forming part thereof,an embodiment of the invention is illustrated diagrammatically by way ofexample.

In the drawing Fig. 1 is a section of the lower part ofthe combustioncylinder of an engine according to this invention.

Fig. 2 is a. section on the line IIII i rig. '1'

and

Figs. 3, 4 and 5 are cylinder deevlopments ilof the cylinders withoutaddlustratine the different phases of the supercharg ing; periodaccording to the invention.

Referring to the drawing and first to-Figs. 1 and 2, in the cylinderreciprocation is shown in its outer dead centre position, in which it,uncovers the scavengin ports 3 to which scavenging air is supplied throuh a conduit ,4. v

Above the scaven ing ports .3 a row f main superchargin p rts 5 and a scond row or additional superchar ing ports '6 are provided. Compressedsupercharging air is fed to these ports in a manner well known in theart. The ports 5 are arranged in that portion of the cylinder wall whichisswept by the piston edge during the supercharging period, while thewall p01- tion, in which the ports 6 are formed, is not yet swept by thepiston when the supercharging period, has come to an end.- Thecircumferential widthof the ports 5 6 than the width of. the.intervening wall portion The slots Ill and and the width of "theadditional ports 6 is only about half that of themain'po'rts 5.

0n the other hand thehumber of additional ports 6 is. greater than thenumber of main ports 5. .Theicylinder .l is surrounded by a ring valve 8which is formed with two rows of slots 10 and H which correspond innumber, size and spacing to the ports 5 and 6, respectively, in thecylinder. I! are so staggered relative to circumferential direction,that the ring valve all port 5 and valve is oscillated by means of adriving lu 9 acted upon by a rod I 4 oprat ng a ainst the action of aspr ng 5 a d bein actuated by a cam shait IBQm unted for rotation in theengine fr me nd carry n m e s I! (Fig. 2).. The lug 9 is arranged on thering valve 8 on the level of the interstice between the ports 5 that.are controlled by the piston and the p r s 6 hat are controlledexclusively by theslide valve, whereby the stress exerted by the lug 9on the sleeve is appropriately distributed.

The stroke of the ring valve is greater than the width of the ports 5 bythe amount required for closing said ports in a pressure-tight mannerand on the other hand completely uncovering them. The additional ports 6and each ther in the in one position of 6 re clos d- The wide as theports 5 and therefor are completely I a piston 2 arranged for I issomewhat smaller working piston,

, to the compression Figs. 3 to 5 illustrate the relative positions ofthe working piston and the ring valve relative to the superchargingports at three consecutive times, the ports 5 and 6 in the cylinder wallbeing schematically illustrated for different time moments. Inthesefigures the slots 3, 5 and 6 in the cylinder wallare shown in fulllines, while the slots Ni, ii in the valve ring are shown in dash lines.The contour of the portion of the cylinder wall swept by the piston areindicated by the chain-dotted line [2 and the hatched surface l3respectively.

Fig. 3 illustrates the positionofthe parts at piston and the the end ofthe scavenging period.- Here the su-- percharging ports 5 and 6 arestill covered by the ring valve and the piston moving away from theouter dead centre is on the verge oiclosing the. scavenging ports 3.Approximately at the same time the exhaust ports arranged at the upperend of the cylinder are closed by the valves 2|.

Fig. 4. illustrates the position of the parts in the middle of thesupercharging period. The main ports 5 are half opened, the additionalports 6, beingnarrower, are open altogether. In the sec- 0nd half of thesupercharging period the ring valve uncovers the ports 5 completely,whereas the narrower ports 6 are closed again.

Fig. 5 illustrates the condition existing at the end of thesupercharging period. The ports 6 are closed by the ring valve, and theports 5 are left open by the valve, but are covered by the workingpiston. As the working piston moves on, the compression stroke begins.After the additional ports 6 have been covered also by the the ringvalve 8 is returned into its initial position shown in Fig. 3.

The mechanism above described as forming an object of the invention actstowardimproving' the supercharging of the cylinders-by increasing duringthe first part, for instance during the first half, of a normalsupercharging period the crosssectional area of the passage admitting thsupercharging medium into the cylinders.

I wish it to be understood that I do not desire V to be limited to theexact details shown and described, ior obvious modifications will occur.to a person skilled in the art.

I claim:

1. An internal combustion engine comprising in combination, a cylinderand a piston arranged for reciprocation therein, exhaust ports in saidcylinder near the compression stroke end of said piston, exhaust valvefor said ports,'a ring valve concentric with and contacting saidcylinder, and two pairs of registering belts of intake ports arranged inaxial alignment in said valve and in the part of the cylinder wall sweptby said piston respectively, said pairs of parts being controlled bysaid ring valve, the ports in the belts nearer stroke end of saidcylinder being materially narrower than the ports in the belts fartheraway from said cylinder end, and means for oscillating said ring valve.

2. An internal combustion engine comprising in combination, a combustioncylinder and a, piston'arranged for reciprocation therein, exhaust portsin said cylindernear the compression stroke end of said piston, exhaustvalve for said ports, a ring valve concentric with and contacting saidcylinder, and two pairs of registering belts of intake ports arranged inaxial alignment in said valve and in the part of the cylinder wall sweptby said piston, respectively, said pairs of ports being controlled bysaid ring valve, the ports in the belts nearer to the compression strokeend of said cylinder being materially narrower and of greater axiallength than the ports in the belts farther from said cylinder end, andmeans for oscillating said ring valve.

3. An internal combustion engine comprising in combination, a combustioncylinder and a piston arranged for reciprocation therein, exhaust portsin said cylinder near the compression stroke end of said piston, exhaustvalves for said ports, a ring valve concentric with ing said cylinderand two pairs of registering belts of intake ports arranged in axialalignmentin saidvalve and in the part of the cylinder wall sweptby saidpiston respectively, said pairs of ports being controlled by said ringvalve, the ports the belts nearer to the compression stroke end of saidcylinder being materially narrower and of greater axial length and morenarrowly spaced than the ports in the belts farther from said cylinderend, and means for oscillating said .ring valve.

4. An internal combustion engine comprising in combination, a combustioncylinder and a piston arranged for reciprocation therein, exhaust portsin said cylinder near the compression stroke end of said piston, exhaustvalve for said ports, a ring valve concentric with and contacting saidcylinder and two pairs of registering belts of intake ports arranged inaxial alignment in said valve and in the port of the cylinder wall sweptby said piston respectively, said pairs of ports being controlled bysaid ring valve, the ports in the belts nearer to the compression strokeend of said cylinder being about half as wide and about double as longas the ports in the belts farther from said cylinder end, and means foroscillating said ring valve.

5. An internal combustion engine comprising in combination, a combustioncylinder and a piston arranged for reciprocation therein, exhaust portsin said cylinder near the compression stroke end of said piston, a beltof intake ports in the cylinder wall near the suction-stroke end of thecylinder and{ two additional belts of intake ports in the cylinder wallin axial alignment with said first belt, a ring valve concentric withand contacting the part ofsaid cylinder formed with said two additionalbelts of intake ports, said-valve being formed with two belts of portsregistering with said additional cylinder ports, the intake ports insaid cylinder and said valve which are next to the compression strokeend of said cylinder being narrower than the intake ports forming theaxially adjoining belts and means for oscillating said ring valve.

6. An internal combustion engine comprising in combination, a cylinderand a piston arranged for reciprocation therein, exhaust ports in saidcylinder near the compression stroke end of said piston, an oscillatoryring valve concentric with and contacting said cylinder and two pairs ofregistering belts of intake ports arranged in axialaligmnent' in saidvalve and in the part of the cylinder wall swept by said piston,respectively, the width of the ports in the belts nearer to thecompression stroke end of said cylinder in the direction of the movementof the ring valve, being about one half of the width of the ports indthe belts farther remote from said cylinder en '7. An internalcombustion engine comprising in combination, a cylinder and a pistonarranged for reciprocation therein, exhaust portsin said cylinder nearthe compression stroke end of said piston, an oscillatory ring valveconcentric'with and contacting said cylinder and two pairs ofregistering belts of intake ports arranged in axial alignment in saidvalve and in the part of the cylinder wall swept by said piston,respectively, the width of the ports in the belts nearer to thecompression stroke end of said cylinder in the direction of the movementof the'ring valve, being about one half of the width of the ports in thebelts farther remote from said cylinder end, 1; e stroke of the ringvalve being about equal to the width of the latter ports.

PIERRE LEBET.

